Supersonic Renaissance: Can Speed and Sustainability Coexist?

Nearly 70 years after the Supersonic Transport Aircraft Committee formed and began investigating the potential of supersonic jets, a new wave of designs is emerging; will the models-in-the-making today ensure or impede the aspirations for sustainable aviation?

Earlier this year, American Boom Supersonic’s experimental jet XB-1 broke the sound barrier, reaching the speed of Mach 1.122. Lifting off from California’s Mojave Air & Space Port, the moment echoed the historic accomplishment of the Bell X-1, which flew in the same location in 1947, flying faster than Mach 1 for the first time in human history.

Marking renewed ambitions to bring supersonic flight back to commercial airlines, promises of great speed have raised significant questions about their environmental impact. Over two decades since the legendary Concorde made its last flight, the question remains: will its successors overcome the issues that led to its retirement?

supersonic jet Concorde — In the Photo: British Airways Concorde G-BOAC, May 1986. Photo Credit: Eduard Marmet.

The New Contenders

The supersonic race of the Cold War era was defined by three major contenders: the USA’s Boeing 2707, the USSR’s Tupolev Tu-144, and the UK-France’s Concorde. Among them, only Concorde succeeded in entering the commercial market. Today, contenders in a supersonic resurgence race include Boom Supersonic (USA), Comac (China), and Venus Aerospace (USA), chasing ambitions to re-establish super-fast air travel, this time for good.

Founded in 2014 by CEO Blake Scholl in an Oakland basement, Boom is now leading the commercial supersonic charge with its flagship project: Overture. The company’s use of computational fluid dynamics testing for the XB-1 model — a prototype of Overture — has led to a substantial reduction in development costs.

boom overture supersonic jet — In the Photo: Boom Supersonic’s Overture. Photo Credit: Boom.

“We can run the equivalent of hundreds of wind tunnel tests overnight in simulation for a fraction of the cost of a real wind test,” Scholl stated.

Set to enter service in 2029, the Overture already has 130 orders from American Airlines, United Airlines, and Japan Airlines. Boom opened its superfactory last year, and it is estimated that it will be manufacturing 66 Overtures annually. Signalling its commitment “to build sustainability into its entire aircraft program,” Boom’s bespoke propulsion system, Symphony, has been designed to run entirely on Sustainable Aviation Fuel (SAF).

However, with supersonic jets requiring significantly more fuel than subsonic and SAF representing only 0.5% of jet fuel currently used due to its scarce and expensive production, such aims could be deemed overambitious, at least for now.

Across the Pacific, China’s Comac is developing its supersonic vision as well; its C949 jet is projected to reach speeds of Mach 2.04, surpassing Overture’s 1.7. Compared to Concorde, the C949 jet promises a 50% greater range (6,800 miles) and a 95% reduction in noise.

Comac’s innovations to combat pollution reportedly include a “shape-shifting” fuselage to reduce sonic booms and noise disruption, and AI-driven aerodynamics to maximize fuel efficiency. With a debut planned for 2049, C949 represents a longer-term strategy to lead in both speed and sustainability.

Then, something of a hybrid between a rocket and an aircraft comes Venus Aerospace‘s hypersonic Stargazer M4 jet — a science-fiction fantasy hoping to become a reality. The jet will target speeds of Mach 4 — and potentially Mach 9 — with a top cruising altitude at the edge of space: the Karman line.

Powered by an innovative rotating detonation rocket engine, a next-generation propulsion system that Venus claims is both more powerful and more fuel-efficient, the Stargazer has attracted support from NASA and the U.S. Department of Defense. If successful, it could redefine commercial air travel by the 2030s.

Sustainable Supersonic Jets: A Farce or Achievable?

While the resurgence of supersonic travel is stirring excitement, it is accompanied by a chorus of concern. Supersonic jets burn significantly more fuel per passenger than subsonic ones. According to estimates, each passenger seat in Overture’s 64–80 capacity aircraft will use 2 to 3 times more fuel than a standard business/first class cabin.

Thus, the promised affordability of supersonic flights is called into question. Will they repeat the Concorde’s financially unsustainable exclusivity or revolutionise the aviation industry?

Moreover, as supersonic jets cruise at higher altitudes — well into the stratosphere — emissions such as nitrogen oxides (NOx) and water vapour may have more serious implications for ozone depletion and radiative forcing. However, according to the International Civil Aviation Organization (ICAO), assessment of the environmental impact of modern supersonic civilian aircraft is limited; with none currently in operation, data is insufficient.

Beyond emissions volume and fuel type (traditional jet fuel or SAF), the factors affecting a jet’s climatic impact and fuel efficiency include fleet size, aircraft technology, speed, and flight path.

SAF, often hailed as a solution to aviation’s CO₂ emissions, may currently be out of reach as a saving grace. Derived from biomass, recycled materials, and even captured carbon, SAF remains scarce and expensive at present. But international investment is growing, with efforts focused on innovation and scaling up production.

The EU’s ReFuelEU Aviation initiative, for example, aims to increase the share of SAF at European airports from just 2% in 2025 to 70% by 2050 — an ambitious target that, if met, could significantly reshape aviation’s climate footprint.

Lessons from Concorde

The shadow of Concorde still looms over the industry. A technological marvel when it entered the industry in 1976 with British Airways and Air France, one problem after another led to its retirement in 2003. High operational and maintenance costs undercut its appeal; the noise pollution made it impractical for overland routes; its engines were inefficient by modern standards; mounting environmental and safety concerns further eroded public support, and eventually, demand waned.

Unlike Concorde, today’s supersonic jets are being designed with sustainability, efficiency, and digital optimization in mind. Boom’s engineers have developed an airframe made of carbon fiber composites, which are both lighter and stronger than traditional metals. In theory, this could lead to a significant reduction in fuel burn.

Aiming to make supersonic travel viable over land, both Boom and Comac are working to reduce noise levels of supersonic jets, seeking to avoid the glass-shattering sonic booms that once confined Concorde to transoceanic routes. In parallel, NASA is researching low-boom technologies to create less disruptive shockwaves. Comac may win the gold medal if it succeeds in making C949’s “noise level like a blowing hairdryer” as the company claims it could.

Yet, even with all the promises of greener technology and quieter skies, the same fundamental challenge remains: is there a viable market for supersonic travel that is both profitable and sustainable? If so, will it extend beyond the global elite?

Between 1990 and 2019, aviation made major strides in energy efficiency, cutting the fuel required per passenger-kilometre from 2.9 megajoules (MJ) to 1.3. However, with flight demand quadrupling over the same period, aviation’s emissions increased overall. Even if the promises of improved efficiency and eventual affordability are met, will large increases in demand, particularly for intercontinental travel requiring more fuel, lead to greater environmental impact?

Looking to the Future: Aviation’s Race to Decarbonise

Commercial aviation accounts for roughly 2.5% of global CO₂ emissions, but its total impact on warming is closer to 4%, factoring in non-CO₂ pollutants and contrails. Across the board, aviation’s survival in a carbon-conscious world depends on scaling up SAF, electrifying regional aircraft, and developing new propulsion systems — from hydrogen to hybrid-electric.

With international commitment being promoted by the EU’s ReFuelEU Aviation’s initiatives and ICAO to avoid patchy progress and uneven regulation, a more sustainable supersonic future in aviation may be achievable through international cooperation.

However, as alluring as futuristic supersonic — nay, hypersonic — flight may be, pouring billions into ultra-fast jets might be a high-stakes gamble, especially for what could prove to be a niche market or a repeat of Concorde’s costly missteps. Critics may argue that such investment may be premature, potentially diverting resources from more scalable green innovations — technologies that could offer a more reliable path toward sustainable progress in aviation.

boom supersonic jet — In the Photo: Boom XB-1 Flight 10, Dec 19, 2024. Photo Credit: Boom.

Supersonic jets have marked a return, not just in engineering labs and factories, but in the public imagination. Driven by a blend of nostalgia, innovation, and national pride, the motivations of the sixties persist; nevertheless, the world they enter is greatly different from the one when Concorde first appeared. Greater dedication to environmental targets, stronger public scrutiny, and larger equity concerns cast long shadows across their glossy fuselages.

Will it be Boom, Comac, or Venus to reel in a new golden age of flight — speedier, cleaner, smarter — or an unsuspecting underdog? Or will the perpetuity of innovation be sacrificed for a quick spectacle, ushering in another hiatus to realising a science-fiction fantasy?

Editor’s Note: The opinions expressed here by the authors are their own, not those of Impakter.com — Cover Photo Credit: Boom.